Sanitary pump



June 23, 1953 p. F. THOMAS 2,642,308

smxmz PUIIP Filed May 17, 1948 2 Sheets-Sheet 1 INVEN TOR.

F' I [E 3 DAVID R THOMAS D. F. THOMAS SANITARY PUIIP June 23,1953

2' Shaw -Sheet 2 Filed llay 17, 1948 n O '2 2; 1n 9. M Q

INVENTOR. DAVID F. THOMAS Patented June 23, 1953 SANITARY PUMP David F. Thomas, Minneapolis, Minn., assignor to Waterous Company, St.'Paul, Minn., a corporation of Minnesota Application May 17, 1948, Serial No. 27,521

My invention relates to an improvement in sanitary pump of a type which may be used for pumping foodstuffs and the like.

In recent years. it has become increasingly desirable to handle various pulpy, liquid, and semiliquid materials by the use of pumping systems. Rather than to convey liquid or semi-liquid foodstuffs from place to place, the material has been pumped from one place to another by means of suitable pumping equipment. In order to accomplish this result in a sanitary manner, the pumps used for the purpose must be designed sothat they can be easily taken apart and cleaned after intervals of use. Thus in such structures, itis desirable to provide pumps which can beeasily taken apart and reassembled for cleaning pur- A feature of the present invention lies in the provision of an impeller compartment which is split in such a manner that the pump chamber is partially formed in each of two removable wall sections. As a result neither section is provided of the pump chamber as the chamber is divided between the two wall sections I I A feature of the present invention lies in the provision of a gear chamber which may be en tirely sealed and which acts to drive two parallel rotatable sleeves. As a result the impellers may be provided with integral impeller shafts which chamber without danger of having these shafts contaminated by grease or oil.

A feature of the present invention resides in the fact that the impellers may be integrally connected tothe drive shaft. As a result one side of each impeller is not subject to leakage as it leads only to a recess in the pump chamber wall and is thus entirely sealed. As a result it is'only necessary to seal one side of the impeller against leakage.

An added feature of the present invention lies in the provisionof a sanitary pump having seg- 9 Claims. (01. 103-126) ment shapedimpellers which project beyond the end of the supporting shaft. In the past it has been common practice to supportthe impellers or rotor in a direction to encircle a part of the supporting shaft. In the present case, the impellers project beyond the end of the supporting shaft and may encirclea fixed portion of the housing end wall.

These sleeves are driven in unison by p drive shafts.

' An added feature of the present invention lies in the specific drive device by means of which the rotors or impellers are rotated. The impeller shafts are rotatedin unison with the sleeves into .which they are inserted. The sleeves are rotated by intermeshing gears so that the rotors will operate in unison and in timed relation. The intermeshing gears are operated by a drive gear mounted upon a drive shaft for engaging one of the gears on one of the sleeves. I

An added feature of the present invention lies in the small number of parts which must be removed in taking the pump apart for cleaning or sterilizing. The six wing nuts supporting the pumping chamber housing walls and the two nuts holding the impellers in place must be removed- The two housing walls may then be freely removed as well as the combined impellers and Seals are interposed between the rear side of ea-chimpeller and one of the housing walls, and this sealing means should preferably be removed during the cleaning operation. Thus an extremely small number of parts must be removed for the cleaning operation.

These and other objects and novel features of w my invention will be more clearly and fully set '35 with an extremely deep cavity forming a part may be removed or withdrawn from the gear no ation forth in the following specification and claims.

In the drawings forming a part of my speci- Figure 1 is an end'elevational view of the pump in assembled form with head, impellers, housing,

and seals removed.

Figure 2 is a view of the pump' with the forward body wall thereof removed.

' Figure 3 is a top plan view partly in along the line 3-3'of Figure l.

Figure 4 is a vertical sectional view through the pump. v I

The sanitary pump A illustrated in the drawings is most completely illustrated in Figure 4. of the drawings. It will be noted that the pump A includes a forward portion illustrated'in general by the numeral l0 and including a pump chamber, impellers, and the like. The pump also includes a rear section II which forms a gear chamber and encloses the gears and impeller shaft supports. The gear chamberll is supported by a longitudinally extending web 12 and section a transversely extending web |3 to a horizontal supporting plate H which may be bolted or otherwise aflixed to a supporting platform or the like.

The gear housing II is rounded at its rear end and includes an integral end closure wall |5. The wall I5 is provided with a pair of parallel apertures H5 and I1 extending partially therethrough and communicating with larger diameter apertures l9 and 20 extending the remainder of the distance therethrough. A ball bearing 2| is supported in the large diameter portion l9 of one aperture and a similar ball bearing 22 is supported in the large diameter portion 20 or the other aperture.

The other end of the gear housing II is provided with an inwardly directed fiange'23 through which a pair of bearing cartridges 24 and 25 extend. The bearing cartridges 24 and 25 are generally cylindrical in shape but are cut away along 'their adjacent sides as indicated at 26 so that the two cartridges may fit closely together. A

' pair of ball bearings 21 and 29 are provided with- "the bearings 21 and 29 in place.

in the cartridge 24 and a similar pair of bearings 30 and 3| are provided within the cartridge 25.

and the aligned bearing 2| in the rear wall I5. A "sleeve 36 is provided with an enlarged diameter end 31 against which the bearings 21 and 29 may modate a lock nut 40.

circles the sleeve 36 adjacent the bearing 29 to engage to hold the sleeve from axial movement. The sleeve is externally threaded at 39 to accom- A spacing sleeve 4| enhold this bearing spaced from a pilot gear 42. The nut 49 engages against the pilot gear 42 to hold the pilot gear and bearings 21 and 29 in fixed relation upon the sleeve. A lock washer 43 f holds the nut 46 from accidental disengagement.

A similar hollow sleeve or mandrel 44 is supported by the bearings 39 and 3| and the aligned j bearin 22 in the rear wall l5. The sleeve 44 is provided with a large diameter end 45 against which the bearing 39 may engage.

A spacing sleeve 46 encircles the sleeve 44 between the bearing 3| and thepilot gear 41. The pilot gear 41 opposit and in mesh with the pilot gear 42. "A nut 49 is threadably engaged on the sleeve 44 3| in fixed relation to the sleeve.

to hold the pilot gear 41 and the bearings 39 and A lock washer 56 prevents accidental disengagement of the nut 49.

The bearing cartridges and retainers are held in place by means of a gear compartment closure I wall 5 This closure wall is provided with spaced apertures 52 and 53 through which the enlarged diameter ends 31 and 45 of the sleeves 36 and 44 A may extend. Cap screws 54 secure the cartridges 24 and 25 to the closure plate 5|.

The closure plate 5| is secured to the end of the gear casing H by means of cap screws or countersunk bolts which are off-set from the particular sections illustrated and which are indicated in Figure 1 by the numeral 55.

In order to entirely close the gear compartment, a seal 56 encircles the large diameter portion 31 of the sleeve 36 and a similar seal 51 encircles the large diameter portion 45 of the sleeve 44. These seals 56 and 51 fit between the sleeves and the end closure wall 5| to seal this end of the gear casing. Seals 59 and 66 are interposed between the other ends of the sleeves 36 and 44 and the walls of apertures l6 and H so as to form a seal at the other extremity of th gear housing externally of the ball bearings 2| and 22.

In order to drive the sleeves 36 and 44 in unison I provide a drive shaft 6| which extends into the rear end of the gear case M as illustrated in Figure 3 of the drawings. The shaft 6| is slightly below the center between the gears 42 and 41 and is provided with a pinion 62 which engages the lower gear 41. The shaft 6| is supported by a ball bearing 63 and a ball bearing 64 mounted in the longitudinally extending aperture 65 in the gear case. A spacing sleeve 66 is interposed between the ball bearing 64 and the bearin 63 and is held in proper spaced relation by a set screw 61. A sealing ring 69 seals the bearing 64.

The closure wall 5| is provided with a forwardly extending flange 19 which extends the major portion of the periphery of this wall but which is discontinued at points spaced from the central spacing boss 1| at the lower edge of the housing so that the space forwardly of the closure wall 5| is open to atmosphere. Thus any grease or oil leaking from the gear case may drain from the casing through the open bottom end thereof at this point and any material being pumped, leaking from the pump chambers may also drain from the casing at this point. In other words, the open space on opposite sides of the center spacing boss 1| acts to separate the pump chamber from the gear chamber and to allow any material leaking from either chamber to drain from the casing.

The pump body 12 is provided with a pair of intersecting impeller chambers 11 and 19 therein, the outline of which is best illustrated in Figure 2 of the drawings, the section of which is best illustrated in Figure 4 of the drawings. These intersecting impeller chambers 11 and 19 communicate with smaller diameter openings 60 and 8| respectively. These openings and BI are spaced and are designed to accommodate the impeller supporting discs or cylinder portions of the impeller shaft supporting the impellers themselves. The apertures 89 and 8| terminate in 'rabbeted double shoulders 82 and 83 for accommodating a sealing element as will be later described.

The intersecting impeller chambers 11 and 19 are continued in the pump casing head 13, this head being provided with intersecting ring shaped apertures 84 and 85 which are aligned with the apertures 11 and 19. The head 13 is likewise provided with a rearwardly projecting central boss concentric with each of the chambers or apertures 84 and 95. These bosses 96 and 91 are designed to extend within the impellers and to complete the pump chambers. In other words, the pumping chambers extend between the central bosses 86 and 81 and the chamber forming recesses 11 and 19, and their extensions 84 and 65.

The impellers are integrally connected to impeller shafts 9| and 92 having a proper outside diameter to fit through the sleeves 36 and 44 respectively. The. sleeves are provided with large diameter aperture portions 93 and 94 respectively which snugly fit about a large diameter portion snugly fitting bearing portions are indicated at 89 andSfl. The major portion of the length of the shafts SI and 92 are of somewhat smaller diameter as indicated in Figure 4 to fit freely within the smaller diameter apertures 91 and 99 of the sleeves 36 and 44. The ends of these impeller shafts are threaded as indicated at I and IOI respectively to accommodate fastening nuts I02 and E03. These nuts hold the impellers and impeller shafts in place withinthe hollow shafts or sleeves 36 and 44. The impellers include hubs I04 and I05 respectively which engage against the forward ends of the hollow shafts 36 and 44. As illustrated these hubs I 04 and I05 interlock with the forward ends of the sleeves 36 and so as to rotate in unison therewith. The hubs I04 and I05 are provided with flattened sides such as I06 and the sleeves 36 and 44 are notched at their forward ends and thus provided with forwardly projecting shoulders I01 which interlock into these flattened sides I06. As a result the sleeves rotate in unison with the impellers and act to drive the same. The impellers are arranged to travel in intersecting paths and to pump fluid or semi-fluid material from the inlet to the outlet. The entire impeller, hub and shank assemblies may be termed impeller units.

As indicated in the drawings an inlet port I09 and an outlet port IIO are provided on opposite sides of the casing extending through the pump body 12. These ports I00 and H0 are provided within projecting bosses which may be externally threaded to accommodate a suitable fitting. Either port may serve asthe inlet and either port may serve as the outlet depending upon the direction of rotation of the impellers.

A seal is provided between the impeller hubs IE4 and I05 and the wall or cavity within the pump body 14. A ring shaped sealing member 44. ;When it isdesired to clean the pump, it is only necessary to remove the wing nuts 16in order to remove the pump head 13. By removing the nuts I02v and; I03 at the opposite end of the shaft the impellersand-their integral shafts may be removed from; the pump. When the impellers are removed thepump body 12 may be removed from the studs 15. The sealing elements which are interposed between the pumpimpellers and the pump body may then be removed and cleaned if desired. Asa resultall of the parts forming III encircles the hub I04 and is held in place by a sliding engagement between the sleeve and the rabbeted wall 82 of the pump body I2. diameter portion II2 on the ring III fits within the cylindrical bore II3 of the body wall and a, smaller diameter portion I I4 of the sleeve I l I fits within the smaller diameter opening I I5 of the body wall. An 0 ring I16 is Provided between the two different diameter portions of the ring and the two different diameter portions of the wall. A spring I I1 is interposed between the base of the larger diameter portion 80 of the body wall ring and the body wall to act as a seal therebetween. A spring I22 encircles the ring I 20 and is interposed between the body wall and a projecting flange I23 on the ring acting to urge the ring against the end surface of the impeller hub to act as a seal therebetween.

The advantages of my construction are believed obvious from the foregoing description. Any fluid or semi-fluid materia1 may be drawn into the pump casing through one portion such as I09 and forced from the other port such as He. The impellers are rotated in unison with their supporting sleeves or hollow shafts 36 and A large a part of the pump chamber may be easilyand quickly removed after removal of the six wing nuts I6 and theltwoshaft nuts I02 and I03.

After the various parts have been entirely washed or sterilized the seals may be inserted into the body portion 12 of the pump and this body portion may be placed over the studs '13.

The impellers may beinserted into place and secured in proper rotative relation by the nuts I02 and I03. The head 13 may then be replaced and the pump isin-readiness for operation.

It will be seen that all of the parts of my pump may be easilycleaned as there are no deeprecesses which are inaccessible for cleanin purposes. By forming the pump chamber partially in the pump body and forwardly in thehead,

the depth of the recesses in which the impeller is recessed is decreased considerably. The impeller shafts are removable with the impellers and the nuts holding the impellers in place are at the opposite end of the apparatus from the pump chamber so that there areno threads within the pumping chamberior near this chamber which might. become contaminated because of the difficulty experienced in cleaning them. The

hollow. shafts which act as the impeller supports do .not extend into the pump chambers and therefore need-not be removed for cleaning purposes. Theends of these hollow shafts 36 and 44 terminate within the open area between the gear case and the pump chamber portions of the.

structure which area is open to atmosphere and therefore is not in aportion, of the pumping chamber. Atthe same time a proper alignment betweenithe impellers and the casing is at all times assured by the structure.

- jInaccordance with the patent statutes, I have described the principles of construction and operation of my sanitary pump and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of spirit of my invention.

I claim:

1. A rotary pump including a gear housing, a pair of hollow shafts rotatably supported by said gear housing, a pair of intermeshinggears on said hollow shafts for rotating said hollow shafts in unison, a drive shaft supported parallel to said hollow shafts in said gear casing, a pinion on said driveshaft engageable with one of said intermeshing gears, a pair of impellers designed for rotation in intersecting paths, and shafts on said impellers removably supported by said hollow shafts and rotatable therewith.

2. A rotary pump including a gear housing, a pump housing removably connected to said gear housing, a pair of impellers rotatable about; intersecting paths, each impeller including an ar cuate segment with curved ends, impeller shafts secured to said impellers and extending into said gear housing, an impeller hub on each of said shafts at one extreme end thereof, said impellers the followin claims without departing from the 7 being connected to said hub to project beyond the end of said shaft.

3. The structure-described in claim 2 in which the pump housing comprises a pump body and a pump head having an impeller chamber therein comprising two intersectingring shaped chamber portions enclosed by encircling walls, said walls being partially formed by both said body and said head.

4. The structure described in claim 2 in which the pump housing includes a body within which said impellers rotate and a head including a boss concentric with, and extending axially toward each said shaft within said impellers.

5. An impeller shaft for a. rotary pump including an impeller hub at one end of the sha-it, impellers integrally secured to said hub and pro jecting beyond the end of the shaIt,-said impellers comprising arcuate segments having curved ends, and threads at the opposite end of said shaft.

6. A pump comprising a pump housing including an impeller chamber,-said impeller chamber including a pair of intersecting ring shaped chamber sections the housing formingencircling peripheral walls, said housing including a body portion and a removable cover portion, the cover portion and body portion being separated between the ends of said encircling :walls defining the periphery of said-chamber.

7. The structure described in claim 6 and including a'p'air of cylindricalbosses on said cover portion forming the inner walls 'of said intersecting ring shaped chambers.

8. A pump construction-including a gear casing, a pair of parallel hollow shafts mounted on said gear casing, means connecting said shafts for causing rotation-thereof in unison, a pair of impeller units remova'bly secured to said shafts, said impeller units including elongated shanks designed to extend through said hollow shafts, and impellers supported upon one-end of each of said shanks and :designed to travel in intersecting paths, impeller hubs on'said shanks designed to extend in abutting relation with an end of the correspondingfhollow shaft, a notch in the end of each of said ihollow shafts, :and "a-projection on each :of said impeller hi1bS engageable 8 into the notch when said impeller shanks are supported within said hollow shafts, said notches and projections holding the impeller in proper angular relation.

9. The structure .described in claim 8 and in which the impeller units are interchangeable.

DAVID F. THOMAS.

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